Method for the utilization of organic waste material

ABSTRACT

Biodegradable waste materials are utilized by forming a suspension in a fermentation tank of comminated waste materials mixed with a microbiological system of a plurality of selected types of microorganisms under conditions to decompose the waste materials. After sufficient microbial metabolic action has taken place, gaseous products and microbial-resistant portions of the suspension are removed. The solid proteineous materials are then separated from the liquor formed in the suspension and the components of the liquor are separated by electrodialysis.

United States Patent 1 1 Metzger 1 51 Jan. 16, 1973 54 METHOD FOR THEUTILIZATION OF 3,386,911) 6/1968 Forrest "210 11 x ORGANIC MATERIAL3,462,275 8/1969 Bellamy ..210/11 X 3,562,137 2/1971 Gehring 204/151 X[76] inventor: James B. Metzger, 20 Cleveland Lane, Princeton, NJ. 08540FORElGN PATENTS OR APPLICATIONS [22] Filed: Feb. 16, 1971 922,148 3/1963Great Britain ..204/151 [21] Appl' 5545 Primary Examiner.lhn H. MackAssistant Examiner-A. C. Prescott [52] US. Cl. ..204/180 P, 204/151,210/11, Attorney-Joel J h son 204/301 51 Int. Cl. ..B01dl3/02 ABSTRACT[58] Field of Search "204/180 1514 210/11 15, Biodegradable wastematerials are utilized by forming 210/16 18, 2; 195/31, 33 a suspensionin a fermentation tank of comminated waste materials mixed with amicrobiological system [56] Refe ce Clted of a plurality of selectedtypes of microorganisms under conditions to decompose the wastematerials. UNITED STATES PATENTS After sufficient microbial metabolicaction has taken 2,158,595 1939 Slagle ..204/151 P gaseous products andmicrobial-resistant p r- 2,259,046 /1941 Roberts ..204/151 tions of thesuspension are removed. The solid 2,796,395 6/1957 Roberts ..204/151proteineous materials are then separated from the 2,799,633 7/1957Roberts 1 1 /l5 liquor formed in the suspension and the components3,268,441 8/1966 Lindstrom ..204/180 P X of the liquor are eparated byelectrodialysis 3,356,609 12/1967 Bruemmer ..210/11 X 3,383,309 5/1968Chandler ..210/11 37 Claims, 2 Drawing Figures 1 2019777770 MYEP W52914145152 flm y/msrzk/nu pwpuc'r au PFEFEEMEA/lflT/OA/ 0F M 44 7 gapC5 6524/647/0/1/ TflA/K a l i F'EME/t/mfifl 0; F rewr 552 gj f w nizlmquzu/a awn/5M5 46H! PEOCESS/A/G 5Z flFifS/f/ZA/T ,y

M47'E/4L5 a; 0 PFZ-T/P/TflT/OA/ 01/0 Mame/4L Z4 ii cygge TqA/KPROCESS/M6 f l /gflwzf T ill/01C ZfiT/UA/ 2,59%; 12 74 El 6750' Him 5 W?///9?47Uf 50 g 5 W 4.

76 l l i i i METHOD FOR THE UTILIZATION OF ORGANIC WASTE MATERIALPotential sources of food for human beings include all energy-richsubstances or materials that in some way may be turned into protein orfats or carbohydrates suitable for human consumption.

The present sources of human food are inadequate. As the population ofthe earth grows, increased protein-deficiencies will come into evidencebefore mass-starvation as such takes place. Whereas a significantproportion of the energy of human beings is derived from the consumptionof dairy products, this represents an inefficient source of human food.Only in the highly developed countries, which are at present well-fed,are milk and dairy products consumed in quantity. The same rationale maybe used in assessing the possibilities of relieving starvation byincreased meat productionit is simply too inefficient and hence tooexpensive to be of value. The livestock of the world, including horses,dairy cattle, and even dogs can only stand as insurance against ashort-term hunger crisis. By eating the corn, fed to hogs, instead ofthe pork itself, can much of the loss in providing food be eliminated.In many parts of the world this expediency has already taken place as anecessity. Microbial or synthetic food, however, appears to be the onlypossible solution to the food crisis that faces the world.

This invention consists of a process for the utilization ofbiodegradable wastes and inexpensive organic and inorganic materials byconverting them into valuable products such as food and fodder, or foodand fodder supplements, organic acids, certain non-toxic acids and otherorganic and inorganic byproducts. Microbial food for human consumptioncan be nutritive, inexpensive, and provide a balanced diet. There areproblems in making the food palatable and in convincing people of itsdesirability. There are also problems in the technology of producing thefood inexpensively.

Whereas garbage and other solid wastes find very limited use inlandfill, they are generally regarded as undesirable wastes, that oughtto be incinerated. In addition to cellulose, other materials are to befound in wastes. While glass and metal can be extracted by mechanicalmeans, lignin, which occurs in varying quantities in the solid wastesgenerally would have to be extracted chemically, because its presenceinhibits the growth of other microorganisms. In the wastes of the paperindustry, the lignin content generally is very high; in garbage it isneglibily low. A high percentage of the content in both garbage andsewage is biodegradable and can serve as energy sources formicroorganisms. Cellulose is probably the most common single organiccompound found on earth today, even discounting the huge quantities ofhydrocarbons, of lignin found in soil, and of peat, and coil. In theUnited States solid wastes are presently 200 million tons annually, andby '1980 are expected to rise to 300 million tons. A very large quantityof these solid wastes consists of cellulose and other biodegradablematerials.

This invention is in a method for the utilization of biodegradable wastematerial comprising (a) forming an aqueous suspension of comminutedbiodegradable waste materials mixed with a microbiological system of aplurality of several types of microorganisms including cellulolyticmicroorganisms; (b) maintaining the suspension in a fermentation tankunder conditions for microbial metabolic action to decompose thecarbohydrates, fats, cellulose in suspension; (c) removing from thetank, during and after the metabolic action the gaseous products of themetabolic action and the portion of the suspension resistant tomicrobial actions; (d) separating the solid proteineous material in thesuspension after the metabolic action from the liquor of the suspension,and (e) extracting the liquid components from the liquor byelectrodialysis. In accordance with features of the invention, amicrobiological system of several types of microorganisms is used forthe efficient conversion of specific varieties of differentbiodegradable waste substrates. A beneficial action of themicroorganisms is established for the protection of the ferment or theentire microbiological system for the deleterious effects of phage orother harmful agents. The product produced by microbial action areseparated in accordance to one embodiment of the invention by means ofelectrodialysis, or dialysis, or electrolytic action. The substances areconcentrated and purified. Flavors or supplemental food additives aremixed with the microbial product for animal or human consumption.

The invention is described with reference to the drawing, wherein FIG. 1is a flow chart indicating the several steps of the process, inaccordance with embodiments of the invention.

FIG. 2 is a schematic diagram showing a battery of cells used indialysis separation of the products of fermentation in the process ofFIG. 1.

With reference to FIG. 1, solid waste materials such as garbage, ortrash of certain kinds is first comminuted by grinding or chopping untilthe material is thoroughly crushed, ground and mashed into fineparticles. Water is added to the fine material into a tank 10 and themixture stirred to provide uniform consistency. The amount of wateradded may vary from 25 percent to 99.6 percent by weight, depending onthe manner in which the mixture is to be handled. The mix resulting fromgrinding and mixing with water is pumped into a prefermentation orseparation tank 12. Here the different waste ingredients are separated,with the heavier materials, as metals and glass, settling to the bottomof the tank and with the lighter materials, such as oils, greases,fats,plastics, wood etc., floating to the surface and providing a floatinglayer. The mix in the separation tank 12 is gently agitated to aid inthe material separation. The heavier materials can be removed in anyfeasible manner and then separated from each other by known procedures,such as magnetically extracting the magnetic metals and separating glassand other such material by sedimentation. The floatation layer is drawnoff and the fats, oils and greases separated from neutral materials andprocessed into soaps, glycerol and fatty acids by conventionalprocesses.

The bulk of the finely comminuted waste material in the separating tank12 remains in suspension. This material is essentially biodegradable andis mainly in the form of sugars, starches and other carbohydratesparticularly cellulose and proteins. Fermentation of these materialsbegins in this tank 12, due to microbial metabolic action of bacterianaturally present. Oxygen is soon removed from the closed fermentationtank 12 by the natural growth of the aerobic bacteria which alsopresent, and which thus protect the anerobes from exposure to oxygen.Specific examples of organisms for the removal of oxygen in theprefermentation tank include: Bacillus subtilis, E. coli, Aerabacteraerogenes and Bacillus proteus vulgare.

The suspension of waste materials is next pumped into-a closedfermentation tank 14. Water may be added to the suspension to provide anoptimum concentration for fermentation. Growth of microorganisms isgenerally most rapid when the water content of the system is high. Thus,5 percent solid matter in the system would beabout normal, but thispercentage can be varied. The fermentation process is preferably one inwhich anaerobic bacteria act on the waste material. The bacterial growthis from bacteria already present in the waste material, when collectedand prior to its comminution, as well as from the bacterial growth inthe separation tank 12. At this time, additional anaerobic factors maybe added to the suspension in tank 14 to speed up the fermentationaction. These may be cultures of rumen microorganisms or a variety ofthermophilic bacteria.

There are three main groups of cellylolytic microorganisms. The groupwhich is selected to be employed in the fermentation or in the synthesisof microbial food will depend on the nature of the substrate, the sizeof the ferment, and the general physical conditions in the areas wherefermentation is to take place. Rumen microorganisms are in general themost fastidious. While these are mesophilic microorganisms and can becultured at moderate temperature (e.g., 3540 C.) they would generallyneed extra amino acids and organic materials to stimulate their growth.

A second group of cellulolytic microorganisms are thermophilic andshould be grown at elevated temperatures. Thermophilic bacteria,included in this group, may be grown at temperatures as high as 70 C.These organisms may be grown whenever conditions are such that theferment can economically be maintained at elevated temperatures. In noform of anaerobic fermentation is there a large heat production, themicrobes are very efficient, so that unless the surroundings are warm orthe ferment is very large and has proportionally a small surface area,some type of external source of heat may be necessary for thermophilicmicroorganisms.

A third group of microorganisms are capable of decomposing cellulose andlignin materials that are resistant to the decomposition by the othertwo groups These microorganisms are, in general molds or fungi, althoughsome bacteria can act, in the same way. They include Polyporousversicolor, Stereum hirsutum, Trametes pini, Aspergillus terreus,Penicillium linaceum, Fomes pini, Boletus lepideus, Poria subacida,Lenzites sepiaria, and others. Slow, but effective, composting can beused with these microorganisms to increase the protein content in thematerial utilized. Because these microorganisms are slow and aerobic, acertain amount of air must be kept in contact with the microorganisms;but the amount of air available will generally not be the limiting factoin their growth. Yields of protein tend to be higher with these aerobicmicroorganisms than with their anaerobic counterparts, but there is nosignificant concomitant production of organic acids or alcohols.

Fermentation in the tank 14 is preferably an almost exclusivelyanaerobic process. The-advantage of using anaerobic bacterialfermentation is that little heat is produced and the efficiency of thesystem is high. In addition, valuable by-products are produced, whereascarbon dioxide and water are the only significant products of aerobicmicrooorganisms acting on the waste suspension. Very little heat isproduced in anaerobic fermentation, and thus very little energy is lostas heat. For every pound of cellulose decomposed anaerobically 0.08 to0.13 pounds of microbial food (dry weight) can be expected to besynthesized. For aerobic growth, the yields of microbial foods aregreater, but the efficiency is considerably less. The explanation tothis paradox lies in the fact that most of the energy originallycontained in the cellulose remains tied up in organic compounds such asacetic acid, once the anaerobic fermentation is complete. For aerobicgrowth, there are no such energy-rich by-products.

Both thermophilic and mesophilic bacteria, mentioned above, areeffective in the decomposition of a wide spectrum of organic compounds,in particular cellulose, which forms such a large fraction of the wastematerial used. Among the specific types of cellulolytic microorganismsthat may be used are the following mesophilic rumen microorganisms;Bacteriodes succinogenes, Ruminococcus flavefaciens, Cillobacteriumcellulosolvens, Ruminococcus fibrisolvens, and Ruminococcus albus, andvarious Clostridia.

The temperature of the substrate in tank 14 would probably lie between30 and centigrade. Although some bacteria are capable of carrying onfermentation at cooler temperatures, 10 C. would be the lower limit forthe action. In addition to losing heat to the surroundings, the systemwould lose a considerable amount of thermal energy by the loss of gasesand vapor. If the system were to small, so that heat losses to thesurroundings would cause the temperature to drop below optimum levels,air can be added to the system in order that heat production increaseand fermentation be maintained to optimum temperature levels. Thetemperature of the system would depend on the nature of the bacteriaused for fermentation.

In the main fermentation tank 14, bacteria of the type listed act uponall the components in the mixture. An agitation system (not shown) isused to increase the efficiency of the fermentation and to increase therate of the bacterial action. In addition to the types of anaerobicbacterial that act on the substrate, it would often be advantageous toinclude fungi, molds, and protozoa. If necessary, inorganic nutrientscan be added to the tank 14 in dissolved or suspended fonn for use bythe bacteria. The inorganic nutrients added would include ammoniumcompounds, phosphate, sulfate, potassium, magnesium, and calciumcompounds. These nutrients can be supplied in a form such as processedsewage wastes.

Microorganisms including fungi, molds, and protozoa as well as bacteriaused in the main fermentation process are by nature self-propagating.Because the ferment in tank 14 represents a continuous process, therewill always be large quantities of seed microorganisms to reproduce, asnew substrates are added to the ferment. When the composition of theferment substrate changes due to seasonal changes (e.g., in the fall itwould be expected that a higher percentage of the solid wastes of acommunity would consist of leaves) or other variations, it would bedesirable, if not necessary to alter the composition of the microbialcommunity in favor of those microorganisms that would grow most rapidlyunder the given conditions. At such times and at the initialinnoculation of the fennentation, considerable care is necessary inadding cultures of microorganisms. Because some of the anaerobes such asthe rumen microorganisms Ruminococcus and Succinomonas, are particularlysensitive to exposure to air, it may be necessary to saturate theferment with carbon dioxide and to exclude oxygen. Another problem thatarises stems from the fact that microorganisms take a certain time toadapt to a new environment. There is an initial period in which themicrobial population may actually decline; if the density ofmicroorganisms is below per cc, there is an appreciable chance that themicroorganisms will become extinct before they can adapt to the newenvironment.

Protozoa, bacteria, and other microorganisms (yeasts, molds, fungi) fromnatural or laboratory sources, such as the rumen of a cow or cultures ofsoil, should be added initially to the fermentation vat 14. Alternately,they can be first grown in a small fermentation system 15, allowed tomultiply in it or in progressively larger systems, and finally added asan innoculum to the main fermentation vat 14, when the population of themicroorganisms is sufficient to insure their adaptation and survival.Because microorganisms vary greatly in their ability to adapt to newsystems, population densities for particular strains of microorganismsranging from 10 per cc. of ferment in the fermentation vat to 100,000cc. may be considered to be a safe number. Because the innoculum usedwould normally contain up to 10 microorganisms and at least 10 of anyone type, one part of the innoculum to a thousand parts of ferment wouldnormally be quite sufficient, provided oxygen does not come into contactwith the microorganisms.

Partially aerobic conditions in tank 14, may be desirable for thefixation of nitrogen. The latter, present in air is turned into aminoacids, and eventually protein, by the rumen microorganisms that arepresent in the system. However, the fixation of nitrogen by bacteria isa very inefficient process. Thus, it would be probably advantageous touse other nitrogen sources than air so that the bacteria have enough ofthis essential element. Certain species of Clostridia and Azotobacterare capable of fixing atmospheric nitrogen. Their efficiency, however,is low. Where other source of nitrogen are too expensive, these bacteriamay be used to take nitrogen from the air. For example, air may be blownthrough the prefermentation tank 12, where much of the oxygen would beremoved before passing into the main fermentation tank. Bacteria therewould absorb gaseous nitrogen and convert it into protein. The additionof urea, ammonium salts, nitrates, nitrites, and organic matter can bethe sources of nitrogen for the microorganisms.

The use of more than one strain of bacteria in the fermentation tank 14,indeed the use of many species, has a tremendous advantage. Not only canthe different types of bacteria or microorganisms digest specific partsof the available nutrient, but they do this more efficiently if each hasa specific purpose. NOt all the bacteria would be cellulolytic, not allcould digest protein with facility, and so on. So long as there is awide variety of strains, species, and general availability, themicrobial community will stabilize according to the physical conditionsand the nature of the substrate.

Because the conditions present in the fermentation tanks are notsuitable for the growth of the few pathogenic bacteria present, thelatter would succumb to the competition of the types of microbes thatare suited for life in the system. The presence of protozoa would have abeneficial effect. Protozoa would eat the pathogenic bacteriaindiscriminately and only those bacteria that reproduce rapidly in themedium would survive. Being self-propagating the protozoa would have tobe added only once to the fermentation tank. Thus, the pathogens wouldsoon be engulfed by the protozoa, since the former are unable toreproduce rapidly outside of their optimum media. Representative rumenprotozoa include: Entodinium, Dasytricha and Diplodinium protozoa.

In accordance with another feature of this invention, one method ofinsuring the growth of the proper bacteria only, lies in the ability ofmicroorganisms to immunize themselves against a wide range ofantibiotics. By exposing the desirable bacteria to certainantibioticssuch as tetracyclines they will soon acquire an innunity toit by means of selective evolution and mutation. Un wanted bacteria thatare introduced with the addition of new waste products and have notreceived such irnmunization treatment would remain vulnerable. It wouldthen only be necessary to include one or more species of microorganismsin the system for the production of antibiotics, such as tetracycline.Whether this microorganism would be present in the main fermentationvats or would be produced in a smaller vat 16 using microbial food as anutrient, is a matter of expediency. The latter situation would probablybe superior because it would offer the greatest amount of control overthe level of antibiotics and microorganisms. It would not be necessaryto extract the antibiotic from the mold or other microorganisms, inwhich it is produced; the mold body itself consists of valuable protein,and there is no reason why this should not be recovered.

The process of fermentation in tank 14 generates large volumes ofmethane, hydrogen, and carbon dioxide as well as alcohol; the relativequantities of these gases depends on the nature of the substrate, thetype of bacteria, the temperature, the degree of agitation in thesystem, and the presence or absence of relatively small quantities ofsteering agents.

Because the temperature of the fermenting vat 14 will probably be closeto 40, the vapor carried off by the gases would contain relatively largefractions of the more volatile fermentation products. Thus, it would bedesirable to condense this vapor.

The volatile products of fermentation can be removed by pumps 18connected to compressors, which liquify first the vapor, then the carbondioxide, leaving the methane and hydrogen in gaseous form. The condensedvapor, which would have a high alcoholic content, could be used as asource of industrial alcohol, or directly as a variety of an alcoholicbeverage, with or without appropriate flavoring. If desirable, themethane and hydrogen could be used on the premises as a fuel for heat,motion, or electricity, or they may be sold as byproducts of theoperation. Fuel cells could conveniently convert their energy directlyinto electricity.

The use of steering agents in the process is supplementary. Such agents,however, can be extremely useful in controlling the yield and types ofproducts formed by the microorganisms. For example, because lactic acidproduced by bacterial action is valued at more than twice the price ofthe acetic acid produced, it obviously is desirable to have a highlactic to acetic acid ratio. The halogen derivatives of acetic acid, canhave an inhibitory effect on acetic acid production by bacteria. Also,it is possible to use such an antibiotic as penicillin, produced bymolds in the system for minimal cost, to inhibit only the growth ofstrains of bacteria that naturally produce acetic acid as a mainproduct. The net effect of such inhibition would favor the alternativemetabolism of other bacteria that produce lactic acid.

Also, because methane production accounts for considerable losses ofavailable energy, it may be desirable to limit production of this gas.Small quantities of carbon tetrachloride have definite inhibitoryeffects on methane production by rumen microorganisms. Present inconcentrations of less than one in a thousand, carbon tetrachloride canvirtually eliminate production of methane without serious effects on thegrowth rate or other aspects of the metabolisms of the microorganisms.This effect can only be explained by assuming that the presence of thiscompound interferes with the action of one or more enzymes involved inthe formation of methane. The carbon tetrachloride is not used up, andits expense would be minimal.

The process of bacteria fermentation in tank 14 produces organic acidssuch as lactic, butyric, propionic, acetic, etc. by the bacteriamentioned above. Such acids are preferably neutralized, because, even atconcentrations of the order of 0.1 percent by weight, organic acids inthe fermentation system being to inhibit the growth of microorganisms,unless the mash is partially neutralized by some alkaline substance.Using sodium bicarbonate the concentration of organic acid ions can beincreased by a factor of without producing the corresponding inhibitionthat will take place, if the acids were not neutralized. The optimum pHlevel of the fermentation system is expected to be in the neighborhoodof 5.5, thus, it is undesirable to neutralize the acids completely. Whenthe pH falls below 5.0, however, the growth of most cellulolyticbacteria slows down. Using inexpensive alkalis such as sodium,magnesium, calcium, or ammonium carbonates, or hydroxides, one canmaximize the concentration of organic acids in the ferment. Sodium,magnesium, and calcium acetates, lactates, butyrates, and propionateswould be among the products formed in solution as a result of theneutralization. All of these compounds have utility in the chemicalindustry.

Since there is an inhibitory effect caused by a high concentration ofcalcium ions or other cations, the levels of these ions are neverallowed to interfere with the growth of the microorganisms. Most of themicroorganisms are sensitive to extremes in pHs. The

pH must, in tank 14, therefore, be kept at moderate levels. In general,it would be desirable to maintain a slightly acid pH at 5.0: 2.0. If theacidity is much greater than this, the microorganisms would beinhibited, but this level would allow the minimum amount of alkalineneutralizing agent to be used.

The microorganisms employed in the fermentation process grow as theydecompose the carbohydrates, fats, and proteins. The relative quantityof proteolytic enzymes and microbes present would best be small, andsources of nitrogen other than protein and amino acids should be presentso that there would be a net increase in the amount of protein presentin the system due to the synthesis of amino acids and protein by themicroorganisms. Thus, whereas there would be considerable decompositionof the abundunt, energy-rich carbonhydrates, especially cellulose, muchof the protein originally present would remain untouched, though nowseparated from the encrusting matter previously present.

Because of the small size of most of bacteria employed in thefermentation process they easily remain in suspension in tank 14, butthe larger and more fibrous particles of cellulose and comminutedmaterial tend to sink to the bottom. Because of this tendency, it isnecessary to employ some system of mechanical agitation. After a periodof time, in the order of 60 hours, fermentation and cellular conversionhas taken place, so that a liquid suspension or liquor is withdrawn fromthe upper portions of the tank 14 into a precipitation tank 20. When theliquid suspension is withdrawn, however, it is desirable to leave theunfermented portions behind in the tank for further action by bacteria.The liquor is substantially free of crude fiber, lignin, and otherindigestible materials originally present in the waste material. A highproportion of the liquor consists of fermentation waste productsincluding ethanol, organic acids, and possibly such compounds as acetoneand glycerol. in addition, there is a substantial quantity of suspendedmatter which contains more than 65 percent protein (dry weight) in theform of viable bacteria, dead bacteria, and plant protein. A certainamount of amino acids would also be found in the solution. Because ofthe high moisture content of this liquid, it would be undesirable to dryit directly to obtain the valuable nonaqueous components. Whereas theliquid may be centrifuged in order to obtain the solid components,centrifugation would normally be prohibitively expensive. Instead ofdirect centrifugation, a chemical coagulant could be added to thesystem. A chloride, or a sulfate, or another salt of aluminum or ironmay be added to the system in order to precipitate the bacteria andother suspended matter. The quantity necessary to precipitate thesuspended matter in the system is small, ranging from 0.0001 to 1.0percent by weight. When used in conjunction with a centrifuge, thechemical coagulant is very effective; it would shorten the necessarycentrifuging time to a fraction of the time otherwise necessary.

When the liquid suspension is treated with these precipitants and/orcentrifuged, the supernatant liquid will have picked up a small quantityof iron or aluminum salts. This should not have any serious effect onthe properties of the resulting liquid. An alternative method ofconcentrating the solid components of the mixture is by means offiltration, using a ceramic, membranous, or fibrous filter.

Due to the dipoles present in amino acids and for other more complicatedreasons, proteins and bacteria cells can have net electric charges inaqueous solutions. Since like charges repel, the greater the net chargeon the cell walls of bacteria, the less readily will the bacteria sticktogether or coagulate. The net electric charge for cells and proteins,however, depends on the pH value of the solution in which they arecontained. At one point on the pH scale, called the isoelectric point,there is no net charge for the particular type of bacteria or proteininvolved; at this point coagulation would not be inhibited by repulsiveforces. On one side of the isoelectric point the bacteria or proteindevelop a positive charge; on the other side a negative charge. Theisoelectric point depends on the particular type of protein or on themolecular structure of cell wall. The further away the pH value is fromthe isoelectric point, the greater the magnitude of the net electriccharge. In general bacteria have isoelectric points at acid pH levels;values of 2.0-3.0 are typical, and if the pH is fairly close to thesevalues, coagulation is most rapid and efficient. The addition of a smallamount of acid may facilitate coagulation.

Even after most of the particulate matter in the supernatant liquor isremoved from the precipitation tank 20, the liquor pumped into tank 22is far from pure; the low level of organic acids make it practicallyuseless because of the large amount of energy and the equipmentnecessary for fractional distillation. The valuable components of thedilute solution are, therefore, extracted by means of the followingprocess, in accordance with another feature of this invention.

The liquor is pumped or otherwise allowed to go from the collection tank22 through one of several multi-celled electrodialysis batteries 50 ofan electrodialysis apparatus 48. FIG. 2 discloses the details of onebattery 50 in which one of the organic acids in the liquor can beconcentrated and removed.

Electrodialysis is the process by which the relative concentrations ofcertain solutes in water solutions may be increased on one side of amembrane. In this invention, the utility of electrodialysis lies in itsefficiency in the separation and concentration of the components in thefermented liquor. As mentioned above, the liquor components includeorganic acids such as acetic, lactic, propionic, butyric, etc. as wellas acetone, glycerol, ethanol, and amino acid. The electrodialysisapparatus 48 consists of several batteries 50 of electrodialysis cells.Each battery can consist of cells formed by separating membranes,alternate ones of which have the same selectivity, such that eachbattery is operative for the ceoncentration of a particular component ofthe liquor.

Each battery 50 consists of a tank 51, which is separated into cells60-66 by parallel diaphragms or membranes 52-57. An inlet chamber 68opens directly into cells 60, 62, 64, and 66, while cells 61, 63, and 65are closed off from the inlet chamber 68. Cells 61, 63, and 65 opendirectly into an outlet chamber 70, which is closed off from the cells60, 62, 64, and 66.

Concentrated liquor is pumped from the collection tank 22 through aninlet pipe 69 into the chamber 68 and into cells 60, 62, 64 and 66. Theliquor is circulated by being drawn off through openings 72 leading fromthe bottom of cells 60, 62, 64 and 66 into an outlet pipe 74. Initiallycells 61, 63 and 65 and outlet chamber 70 are filled with concentratedliquor from the tank 22. The product of the electrodialysis flows fromthe outlet chamber 70 from cells 61, 63 and 65 and through the outletpipe 78. Within the tank 51 on opposite sides are mounted electrodeplates 80 and 82, respectively. Plates 80 and 82 are connected in serieswith the positive and negative terminals of a source of d.c. potential84, with the circuit being completed through the cells -66 of theelectrodialysis battery 50. The positive plate electrode 80 attractsanions in its direction and the negative plate electrode 82 attractscations in its direction. Between the electrode plates are arranged theion-selective membranes 52-57. Membranes 52, 54, and 56 are treated inthe manner described below to the selective with respect to cations.They permit the free passage of such ions, as positive sodium andhydronium ions, for example, but these same membranes inhibit thepassage of anions, including acetate, propionate, and lactate ions.Membranes 53, 55, and 57 are normally not treated and allow the passageof most ions in the liquor solution.

In operation, the electrodialysis tank 51 is filled with theconcentrated liquor. If the battery 50 is for the separation of aceticacid from the liquor, then membranes 52, 52 and 56 are treated freely topermit the passage of all ions but acetate ions. Membranes 53, 55 and 57are normally untreated, and as mentioned above permit the passage of allions found in the liquor solution. When a potential difference of a fewvolts is applied between the electrodes 80 and 83, a migration of ionstakes place. The concentration of the acetate ions tends to increase incells 61, 63 and as the concentrations of these ions decrease in cells60, 62, 64 and 66. Sodium and other cations drift through all the cellstoward the negative plate 82. The liquid is slowly pumped out of thechamber through the outlet 78. The rate of removal of the liquid is suchthat due to he electrodialysis action the concentration of acetic acidin cells 61, 63 and 65 is about 10 percent by weight. The liquid inthese cells is continuously replaced by osmosis through the membranestending to equalize the concentrations of the solutions in all thecells. Osmosis represents a secondary process, being slower thanelectrodialysis at reasonable current densities. For maximum efficiency,the membranes are placed very close together perhaps in the order of onemillimeter apart. The liquor in cells 60, 62, 64 and 66 is replenishedby a circulating system which draws the spent liquor from cells 60, 62,64 and 66 through the outlet 74 and recycles the liquid back to tank 12and 14.

Whereas membranes would be selected for a combination of desirablecharacteristics including conductivity, permeability, degree ofselectively, length of life, and cost, several types of membranes arecapable of giving good results. Various types of membranes are known.Some of these membranes are selective to the passage of anions (negativeions) or cations (positive ions). For example, membranes treated byprecipitating barium sulfate within the membrane itself have theproperty that neither sulfate nor barium ions will pass through themembrane as readily as other cations or anions. The theory behind thissort of selectivity is that, since the membrane is saturated withsulfate and barium ions (in this particular case), and because likecharges and like ions repel, barium and sulfate ions cannot pass throughthe membrane as readily as chloride, sodium, potassium, or other ions.

The same principle is applied in this invention, but with regard toorganic rather than inorganic ions. Although existing anion-selectiveand cation-selective membranes would be effective in separating andconcentrating organic acids in an electrodialysis apparatus, a specialtype of membrane, in accordance with this invention is both efficientand cheap to produce. These membranes consist of treated cellulosicmaterialsparchment, or Kraft paper, or Cellophane, or other membranes,which are derivatives of cellulose. Cellulose forms esters withvariousacids, resulting in compounds as cellulose acetate and cellulosepropionate. It appears that the presence of even small quantities of theacetate or propionate groups in the membrane have an effect analogous tothe presence of a sulfate group in a barium sulfate precipitationmembrane.

An effective way of combining cellulose with acetate or propionategroups, consists in heating acetic acid anhydride or propionic acidanhydride with cellulose, optionally in the presence of sulfuric acid orglacial acetic acid or pure propionic acid. Under these circumstances,the organic acid anhydride combines with the cellulose to form acellulosic ester of the organic acid. A similar reaction occurs, butwith the concomitant formation of water, when acetic acid or propionicacid react with cellulose in the presence of sulfuric or phosphoricacids, which act as dehydrating agents. Because a membrane consisting ofpure cellulose triacetate is a poor conductor of electricity in anaqueous system, it is impractical. However, in accordance with thisinvention, 1 have found that a cellulosic membrane when soaked inglacial acetic acid at room temperature for about 12 hours and is washedin clear water, it becomes selective with respect to acetate ions. Thatis, acetate ions do not pass as readily through the membrane, sotreated, as do hydrogen, sodium, or other ions. The electricalconductivity of a so treated cellulosic membrane is excellent. If themembranes are treated more drastically, for example with the organicacid anhydride, but not for so long that complete esterification takesplace, the membrane becomes more highly selective towards the passage ofthe ions without prohibitively decreasing the conductivity of themembrane.

This new type of membrane has special utility in the electrodialysisprocess for this invention. Because the liquor contains several organicacids, a membrane selective not only to cations, but also to particularcations serves as an effective means of separating and concentrating oneacid from another. By using several electrodialysis units, one unit foreach type of organic acid that is to be separated, and each type withthe appropriate variety of selective membranes, it is possible to obtaingood concentrations and purities of the individual acids.

The liquid in the collection tank 22 is flowed through the batteries 50of the electrodialysis apparatus, as described. With an organic acidcontent in the order of 1 percent, this liquid is a good conductor ofelectricity, especially if the ions of an alkali metal (such as sodiumor potassium) are present. Electrodialysis is most efficient, if thedifference in concentration of the liquids on either side of themembranes is low. Thus, it is cheaper to extract 1 part of 10 percentacetic acid by electrodialyzing 20 parts of l percent acetic acid andreducing the concentration of these 20 parts to approximately 0.5percent, than it is to extract the 1 part 10 percent acetic acid from 10parts of 1 percent liquor, which would reduce the acetic acidconcentration of these 10 parts to zero. Electrodialysis by successivebatteries of units is more efficient. For example, a 1 percent liquorcould produce a 4 percent product in one electrodialysis unit, and this4 percent solution could be further concentrated to 12 percent in asecond electrodialysis unit. Such multi-step concentration is moreefficient (because the effect of osmosis are minimized), and the productwould be purer. Organic salts can also be concentrated and separatedfrom the liquor by the electrodialysis apparatus disclosed in FIG. 2.For example, membranes 53, 55, and 57 can be treated to be completelydiscriminating to sodium ions, so that sodium acetate becomesconcentrated in cells 61, 63 and 65. The concentrated salt solution isthen removed and dried to obtain the salt.

Taking a portion of the organic acids or salts from a large quantity ofliquor from tank 22 is more efficient than taking an equal quantity oforganic acids from a smaller quantity of liquor. Because the liquor fromwhich the portion of organic acids has been extracted is recycled backinto the fermentation tanks 12 and 14, there is no loss using largequantities of liquor for feeding the electrodialysis apparatus. Theprimary problem encountered in using increasingly large quantities of 1liquor lies in the probability of dissolving oxygen in the liquor. Largequantities of oxygen in the recycled liquor could have a deleteriouseffect on the anaerobic fermentation in the tanks 12 and 14. To avoidsuch an effect, the spent electrodialyzed liquor is best recycled intothe prefermentation tank 12, where aerobic bacteria would use up theoxygen before it could harm the anaerobic bacteria of the mainfermentation tank 14. Under certain circumstances, it might be advisableto allow the effluent to age in a reservoir before returning it to thefermentation tanks 12 and 14, becausethe fresh electrodialysis effluentmay contain some oxidants and, thus, have an inhibitory effect on themicroorganisms.

Because the electrical resistance of the aqueous organic acid solutionsplays an important role in determining the efficiency ofelectrodialysis, it is desirable to minimize resistance. Since a spacingof l centimeter would have 10 times the resistance of l millimeter for agiven cross-section in an electrodialysis apparatus, it follows that thecloser the membranes are spaced, the greater the efficiency (in terms ofpower used to concentrate product). Thus, even in a large scaleoperation, the spacing between the membranes would best be small, in theorder of l millimeter. The actual spacing would represent a compromisebetween the most efficient close spacing and most inexpensively producedelectrodialysis units. In areas where electricity is cheaper, efficiencyin the use of electric power would represent a less importantconsideration and membranes may be spaced more widely apart, if it ischeaper to build them that way.

The following aspects in the electrodialysis process make it effectiveand desirable. In dilute solutions, the

proportion of organic acid ions to non-ionized molecules is relativelyhigh. Thus, the conductivity of the dilute liquor is fairly good.Although the conductivity of the concentrated solution remains good, theproportion of the ions decreases and, thus, does not interfere with theprocess as would a high concentration of ions.

Amino acids contained in the liquor do not pass readily through any typeof selective membrane, and therefore, are returned to the fermentationtank 12 and 14 with the spent liquor. There is no contamination of thepurified, concentrated product with the raw liquor, because there is nodirect contact between the two liquids.

Care should be taken so that the organic acid anions are the principleanions in the electrodialysis system; otherwise the concentrated productpumped off might have an undue amount of sulfate, chloride, or phosphateions. This is accomplished by merely controlling the intake of inorganicions into the original fermentation system.

The concentrated product pumped off need not contain any of theimpurities of the original liquor. The product is comparable todistilled vinegar and could be used as a food, or i t could be furtherconcentrated by conventional means such as distillation, rectification,or evaporation.

Alternatively, the liquor from the fermentation suspension in tank 14could be concentrated by evaporation, or it could be used as the basisof the tart, refreshing drink and food additive. It must be rememberedthat the liquor would contain varying amounts of alcohol and organicacids according to fermentation conditions. Thus, it would becomparatively easy to produce a beverage of low to moderate alcoholiccontent and containing a certain quantity of organic acids and carbondioxide to give it flavor. Again, it would be necessary to sterilize anydrink for human consumption with heat. The liquor in tank 14 could alsobe distilled in order to produce industrial alcohol or cheap distilledspirits. in no case would it be necessary to remove the fermentationproducts and by-products from the liquor completely; any portion of theliquor can be recycled in the fermentation vats. Through the use ofsteering agents, the composition of the liquor could be controlledfurther; the extractive methods would be used according to thecomposition of the liquor.

Excess heat produced by the electrodialysis apparatus could be used, ifit is found expedient, as a free heat supply for the fermentationvessel. The electrodialysis apparatus works at maximum efficiency when alarge, constant flow of liquor goes through the system.

Although the salts of the organic acids formed as a result ofneutralization are valuable, and they may be concentrated by the processof electrodialysis described, the acids themselves may be more valuable.By using membranes in the electrodialysis apparatus that favor thepassage of hydrogen ions to alkali metal ions such as sodium, theconcentrated product will be more highly acidic, and it will containonly small quantities of the alkali metal ions. The remaining solutionwill become quite alkaline and may well be recycled to the fermentationtank 14 to neutralize more organic acids that have been produced asfermentation proceeds.

In accordance with a feature of the invention, the system is organizedto provide an equilibrium condition in the fermentation tank- 14,depending on (1) the nature and concentration of the substrate, (2) thetype of bacteria employed, (3) the presence of steering agents, if any,(4) the rate at which the electrodialysis apparatus withdraws organicacids from the system and (5) the pH of the liquid ferment, which isdependent on the concentration of alkali metal ions.

If the concentration of organic acid ions in the ferment is lowered bythe flow of the liquid suspension from the prefermentation tank 12 intotank 14, for example, then the growth of microorganisism will increaseand their metabolites, such as organic acids, whose production is afunction of their growth rates will also increase. This tends to restorethe ionic concentration in tank 14. However, at lower ionicconcentrations, the efficiency of the electrodialysis apparatus isseriously reduced and less organic acids are withdrawn in a given amountof time or for a given amount of electric power, also tending to restorethe equilibrium condition.

On the other hand, if the concentration of organic acid ions tends toincrease, there is an inhibiting effect upon the growth of bacteria.This may occur at pH 5.0 or lower. Neutralization of the ferment byalkaline salts is then used to prevent the pH from dropping below 5.0.But again, conditions will be reached where the concentration of organicions reaches about 1 percent, by weight. This condition also inhibitsbacterial growth. This condition is balanced since'the increased ionicconcentration results in a greater conductivity of the solution enteringthe electrodialysis apparatus, which is reflected in the increasedefficiency of the electrodialysis and the more rapid removal of theorganic acids, until the point of equilibrium is reestablished. Inpractice only small fluctuations from the equilibrium concentration willoccur unless any of the five factors enumerated above are altered. Inthat case the equilibrium condition will shift.

The concentration of organic acids at equilibrium would lie between 0.1and 10 percent. At concentrations of less than 0.1 percent, the size ofthe fermentation tank and the extra expense in electrodialysis (to makeup for reduced efficiency) would become economically prohibitive: Eventhe hardiest microorganisms would find it difficult to grow, if not evento survive, in a liquid containing more than 10 percent (calculated byweight) of organic acids, even if they were neutralized with alkalies.The optimum concentration represents an economic problem, as well as ascientific one. The cost of electricity and of alkalies, the prices oforganic acid products and other factors enter into play.

If organic salt solutions formed as a result of neutralizing the acidswith alkalies are withdrawn by the dialysis apparatus, the concentrationsolutions of these salts may be dried or cooled, so that the purecrystals of the compounds separate out. In the case of calcium lactate,for example, crystallization is quite practical. This salt is sparinglysoluble in water and will crystallize at low concentrations with aneglible contamination by other compounds.

Organic alcohols and organic acids are produced by microorganisms andare part of the liquor taken from tank 14. Electrodialysis removes theorganic acids, as

described, but the concentration of alcohols and acetone would tend tobuild up. These energy-rich compounds-the alcohols including primarilyethanol and butanolmay be removed from the liquor by providing a mixtureof gasoline and the liquor. Though gasoline (or other hydrocarbonmixtures) is immiscible with water, the alcohol and acetone willdissolve in the gasoline. In accordance to an embodiment of thisinvention, the liquor containing mainly water and some alcohol is mixedvigorously with gasoline. A considerable fraction of the alcohol willpass into the gasoline mixture, increasing substantially the volume ofthe gasoline portion of the system. After thorough mixing, anequilibrium is established so that no more alcohol can pass out of thewater medium into the gasoline, and the ratio of the concentration ofalcohol in the water to the concentration of alcohol in the gasoline isfixed. For ethanol l have found this ratio to be approximately 7:1, thatis, for one volume of aqueous alcohol, there will be seven times as muchalcohol as in one volume of gasoline mixture. For higher alcohols, suchas butanol, and for acetone, the ratio of concentrations is moreadvantageous, allowing a greater amount of alcohols to be extracted fora given volume of gasoline used to extract them. In any case, themixture is then allowed to settle, the gasoline-alcohol layer rising tothe top, andthe aqueous liquor sinking to the bottom of the vessel.These two liquids are separate and distinct and can easily be withdrawnseparately. The gasoline mixture is withdrawn and may be used directlyas a motor fuel. Gasoline containing such small quantities of alcoholdissolved in it has superior properties as a motor fuel, and thequantity of the fuel is increased by the inclusion of the alcohol.

The aqueous liquor, from which only a part of the alcohol'has beenremoved by this process can be recycled to the fermentation tanks 12 and14. The net effect of removing alcohol and acetone from the liquor inthis manner is to remove all of the alcohol without waste and to enrichlarge quantities of gasoline by doing so. By lowering the temperature ofthe extraction below 32F. ice crystals will form, and substantially moreof the alcohol in a given batch will pass into the gasoline phase of thesystem. By a continuous recycling of the liquor virtually all of thealcohol is removed, eventually and the reduction in the concentration ofthe alcohol in the liquor has a beneficial effect on the growth of themicroorganisms in the main fermentation tank 14.

Once the solid, proteinaceous material is separated, it can be processedby equipment 26 in several ways. It may be pasteurized, autoclaved,deodorized, and flavored, to become a high nutritious beverage,outranking even milk. It may be used as the basis or as a supplement forany one of a wide variety of foods or fodder, including soups, breads,and meal. It may be autolyzed with equipment 28 to release flavors bythe addition of proteolytic enzymes at set pH and temperature. Theenzymes already present may be used to convert any starch or cellulosepresent, or added to it, into sugars. This would be achieved byselective destruction and inhibitionof enzymes such as those involved inglycolysis that normally would convert the sugar into acids and alcohol.Thus the product could acquire a sweet taste. Autolysis is the processthat occurs when the proteolytic enzymes of a cell found in thelysosomes are released and bring about the self-digestion of the cell.Autolysis may be brought about by a process that disrupts the lysosomes,so that theenzymes contained in them attack the protein of the cell.Heat, grinding, addition of other proteolytic enzymes, or hydrolysiswith hot mineral acid may bring about autolysis. The amino acids andpolypeptides formed from the proteins as a result of lysis tend to bemore flavorful than the proteins themselves. Boullion cubes and instantgravy often have hydrolyzed vegetable protein. Lysis causes a similarhydrolysis of the proteins of cells.

Degradation of certain proteins would be advantageous in this process,if the protein were otherwise resistant to digestion. The protein foundin compost is of this type. By boiling with a dilute solution (0.5%) ofmineral acid (sulfuric or hydrochloric) hydrolysis will occur, andautolysis may supplement the effect of the acid. Proteinaceous materialtreated in such a manner for about 30 minutes would be easy to digestfor an animal, a human, of another microorganism. Autolysis may also beinduced by means of electrohydraulic shock provided by a high potentialbetween plates, alternated from positive to negative at a highfrequency. The bacteria lying between the plates in the field of thealternating potential are so jostled that their lysosomes are disrupted,and the enzymes released proceed to digest the cell.

Also, the semi-solid proteinaceous material may be sterilized and driedin a sterilizer and oven 30 to a stable powder form, similar to fishmeal. It must be noted that a relatively high temperature should beemployed in order to make the bacterial food safe for consumption.Because of the difficulties of controlling the bacteria cultures, it ispossible although unlikely, that some pathogenic bacteria may bepresent. These should be killed, and they are often resistant to mereboiling. Au-

toclaving the liquid or dry powder will insure not only the sterility ofthe product, but it should also destroy any toxins present that may havebeen formed by the action of bacteria, fungi, or molds. For example,heat will inactivate the entertoxin of Clostridium botulinum, whichotherwise would pose a severe threat to any consumer of the food.

The vitamin content of the bacterial food is very high, especially theB-vitamin content. So long as the autoclaving temperature does not goabove 260F., there will be minimal decomposition of vitamins; thus,controlled autoclaving would not impair the nutritional value of theproduct.

ln order to make the semi-solid microorganism coagulant palatable, oneor more of three general methods could be employed. When it or a productprepared from it is fed to animals, taste is not the primaryconsideration. For human consumption it could, however, be flavored inorder to cover up any objectionable taste. l-lot spices would beespecially effective to accomplish this feat. The flavors and odorsalready present could be weakened or taken away altogether by means ofchemical treatment. The use of alkalies to neutralize amino acids andother flavor and odor-causing substances will reduce the level of bothflavor and odor so that the product is quite bland. Heating and dryingare also effective. Under certain circumstances, it may be desirable tobring out the flavor of the material. This is accomplished by theaddition of enzymes and/or autolyzing.

The proteinaceous solid material from the precipita tion tank 20 mayalso be texturized to simulate meat, in accordance with a feature ofthis invention, by appropriate equipment 32. First, the protein ispurified by dissolving the proteinaceous material in alkali, acid,alcoholic, urea, or biuret solutions. In this process the alcoholsproduced by fermentation in tank 14 may be concentrated and used assolvents for the protein. Strong alkalies (e.g., sodium hydroxide) andstrong acids (e.g., sulfuric acid) are also effective solvents forprotein. In order to texturize the protein to simulate meat, it isessential that protein fibers are formed. A concentrated proteinsolution, in one of the solvents mentioned above, is forced underpressure through the tiny holes of a spinneret. On the other side of thespinneret is a solution and environment in which the protein isconsiderably less soluble. in pure cold water the protein wouldimmediately coagulate into fibers, and these fibers being insoluble areeasily extracted and washed. The protein fibers may be formed into asynthetic meat by binding them together with gelatin or a similarproteineous material.

If hot sulfuric acid or hot sodium hydroxide is used to dissolve theprotein, the solution is forced through the spinnerets and the acid oralkali is immediately diluted.

\ By means of concentrative electrodialysis the acid or I beneficialsource of nitrogen.

Another edible product that can be derived from the described process issynthetic cheese. In place of milk curds, as the basis of this cheese,the semi-solid precipitated proteinaceous material from the tank 20 isplaced in a vat 34. Precisely the same strain of bacteria or mold isadded to this nutrient, as would be added to cure the correspondingcheese. Growth of the microorganism is rapid. The microbial nutrient issuperior to milk in this respect. Flavoring agents such as propionic andlactic acids can be added to the system so as to approximate the flavorof the cheese. Fats and oils may be added, also in order to duplicatethe composition of the natural cheese.

To give the cheese the right consistency and body, it would be necessaryto add a truly curdled proteinaceous material (even a small amount ofmilk protein will do) or to add a material consisting of apolysaccharide or derivative thereof. Starch and derivatives ofcellulose are suitable for the latter. A sodium salt ofcarboxymethylcellulose would be highly suitable. While it would provideno nutritive value to human beings, its presence would add bulk to thediet, and its concentration would be low.

One of the major problems that has existed in the past as a deterrent tothe utilization of microorganisms for decomposing garbage and suchmaterials was the large quantity of noxious wastes after bacterialfermentation and the costs involved in disposing of this apparentlyuseless material. After the main fermentation process for garbage, themass of the solid material remaining would be considerably reduced, butvirtually all of the mineral or inorganic material originally present(if not previously withdrawn by mechanical means) would remain. Inaddition, substantially all of the lignin, a considerable fraction ofthe cellulose and protein, which would be found in the dead bodies ofthe microorganisms would be mixed in with the inorganic material.

Although most of the organic material present in the main fermentationtank 14, should in time decompose, a substantial portion of it is quiteresistant to microbial decomposition. The build-up of such resistantmaterial may actually serve as a mechanical or even chemical block ofthe fermentation of the parts that can otherwise easily be decomposed.Because of this inhibitory effect, it is desirable to flush away theresistant material causing the decrease in the fermentation rate.

The resistant material would be largely composed of lignin, resistantvarieties of cellulose and hemicellulose, other resistant organiccompounds, and non-degradable material. The material would tend to sinkto the bottom of the tank. By means of a flushing system, these may beremoved without disturbing the rest of the system. It must be noted thatthe waste material contains substantial quantities of protein, and thisshould not be wasted. The protein consists in three categories; proteinof bacterial or other microbial cells that were mechanically attached tothe waste, a type of protein resistant to attack and any other proteinsincluding residual protein from the original waste material. In order toextract this resistant material, treatment with strong acid or alkali,dissolving in an organic solvent such as isopropyl or butyl alcohol, ortreatment with proteolytic enzymes or microorganism is applied in theapparatus 90.

One method, which is effective consists of treating the material with asolution of sodium hydroxide in order to release proteinaceous materialinto solution or suspension. This is followed by neutralization andprecipitation of the proteinaceous material using centrifugation orchemical coagulation. This is, of course, followed by drying,autoclaving, or other processing to make the material suitable forconsumption.

Another method includes electrodialysis or dialysis. Since the lignin,most of the resistant cellulose and the resistant materials, other thanproteins, are not dissolved by the process of boiling in solutions ofacids or alkalies, the liquid containing the protein is thus easilywithdrawn. Then, by means of electrodialysis or dialysis the protein andhydrolyzed protein may be separated from the acid or alkali. Inelectrodialysis the acid or alkali is concentrated on one side of themembrane, while the protein is precipitated on the other side.Electrodialysis has the advantage of recovery of the acid or alkali,since the acid or alkali passes to the other side of the membraneleaving the protein and amino acids behind. Dialysis depends on adifference in the concentration of the two solutions on either side ofthe membrane. If the acid or alkali were merely neutralized rather thanseparated from the protein, only a portion of the protein wouldprecipitate, and the salt concentration of the broth would be high.

Protein comprises up to percent of the solid waste of the mainfermentation process. For every ton of raw garbage originally processed,about 200 pounds (dry weight) of resistant material would be producedafter substantially all the free protein and directly utilizablesubstances are withdrawn. Because microorganisms principally fungi-areso slow in attacking lignin, resistant, cellulose and hemicellulose, andbecause the products produced by the main fermentation process and areeven harder to extract, strictly controlled growth of suchmicroorganisms would be economically infeasible.

lnstead of a controlled fermentation the material is placed in an openfield and covered with soil. In a field of 1 acre the compost could bepiled to a height of about 4 meters, and 20,000 tons of compost couldundergo the comparatively slow process of decomposition. To enhance thisnatural process the compost is kept moist and aeriated, and ammonia,phosphate, calcium, potassium, and other inorganic nutrients should beadded to the compost to replace the nutritive material already extractedin the form of protein. Aeriation can be achieved by a combination orany one of the following methods: the inclusion of earthworms or similaranimals that thrive in compost, while stirring up the mixture andallowing contact with air; periodic bulldozing of the field to turn overthe under layers; the compost could also be placed in layers that wouldnot be compressed. Various strains and types of fungi including thegroups classed as white and brown rots could be added to the compost.Because they are selfpropagating, the addition of cultures to thecompost would be necessary only once.

Under the conditions described a minimum of three months would berequired for substantial degradation to take place in the compost. Whilethe weight of the compost would be substantially reduced due to loss ofcarbon dioxide and water to the atmosphere, the absolute as well aspercentage protein content in the compost would rise. Although such agedcompost could serve as an excellent garden mulch comparable to peatmoss, by the end of several months the protein content could rise to asmuch as 20 percent. This protein may then be extracted by the methoddescribed above. Derivatives of humic acids, cyclic organic compounds,and similar substances would also be found in the humus form.Potentially they could serve as a source of organic chemicals if theyare extracted by means of conventional or destructive distillation.

A variation of the system of producing protein from carbohydratesconsists in the inclusion in the human diet of a quantity (0.5 to 30 gm)of urea or ammonium salts or a combination thereof. lnitially it wouldalso be advisable, although not essential to add a bacterial culture tothe diet. In this manner a human being would become capable of utilizingnitrogen from urea or ammonia, both extremely cheap sources. Whereasthere is considerable evidence that human beings, especially infants,are capable of metabolizing urea and ammonium salts as a source ofnonessential amino acid nitrogen, a considerable quantity of the ureaingested could be used by intestinal bacteria]. The ingestion of aparticular strain suitable for symbiotic existence with human beingswould be necessary only once. Starchy foods found in profusion in thediets of many kwashiokor victims would provide the necessary energy forthe synthesis of protein by microorganism within the human digestivetract. Since the quantity of nitrogen egested in the feces is quiteconstant for those whose diet is at subsistance levels with respect toprotein, the added nitrogen in the form of urea or ammonium salts oreasily synthesized amino acids would be utilized by the kwashiokorvictim.

in addition to the nitrogen compound a smaller amount of other cheapinorganic or simple organic nutrients may be included in the diet; theseinclude phophates, calcium, potassium, sulfates, salt, magnesium, andextremely small amounts of iodine, iron, copper, molybdenum, and cobalt.The efficency of these nutrients lies in the same principle as thesynthesis of proteins and other nutritionally valuable materials inlarge vats to which waste materials are added as food as describedabove. This method of supplementing the diets of human beings has theadvantage of being extremely cheap. In addition, unlike other dietarysupplements such as milk and fish protein, this supplement is hardlysuitable for hoarding. To take more than the usual doses at any one timewould result in severe illness or even death; the rich could hardlybenefit by stealing this form of relief from the poor. The manner iswhich the supplement could be administered would have to preclude thepossibility of an overdose; this dietary supplement must be consideredto be a drug or medicine that combats the disease of hunger andstarvation. It could be administered at schools or at special centers inareas of Africa and India stricken by kwashiokor. Because of therelatively small volume of supplements needed, it would not interferewith eating habits or economic situation of an area where it is used.

One important feature in the process of growing bacteria and othermicroorganisms on waste materials consists in recycling a portion of thesyntheized amino acid. The addition of amino acids to an in vitro systemof rumen bacteria increases the rate of growth and the extent of theutilization of cellulose. Although the bacteria present can sythesizeprotein from inorganic sources of nitrogen, the only possibleexplanation for this fact is to assume that some amino acids are eithernot synthesized by certain strains of bacteria or else they aresynthesized very slowly due to some deficiency. By hydrolyzing a portionof the-synthesized bacterial protein, it becomes possible to increasethe overall protein synthesis rate when the resulting amino acids areadded to the system. The bacteria thus share their amino acids and makeup for any deficiency one or two particular strains may have otherwiseas a result of a mutation. I

One important aspect of this invention is the ability of this biosystemto change in time. Whereas natural mutations would tend to producedifferent properties for the new generations of bacteria, it is alsopossible to induce mutations by means of radiation or mutageniccompounds and to keep conditions in the system that should favor oneparticular type of mutation. Not only could the efficiency of thefermentation process improve as the microorganisms adapt themselves tothe prevailing conditions, but even the products obtained from thebacteria could be changed, so that either the yield or the variety ofproducts would be economically expedient.

One example of adaptation among bacteria that is very useful is theincreasing ability of the bacteria to utilize inorganic sources ofnitrogen. By exposing bacteria to ever increasing concentrations ofammonium salts, it is comparatively easy to achieve the adaptation ofthe bacteria to ammonia as a source of nitrogen, replacing amino acids.In this case, the ability of utilizing ammonia probably always existed,but since the bacteria had no need to synthesize amino acids so long asthere was a plentiful supply, the proper enzymes did not exist inquantity and were not put to work for synthesis.

The fact that this biosystem contains at least two tanks 12 and 14,where microorganisms can grow and reproduce is important to thecontinuation of strong, viable strains of bacteria. Should the firsttank become infested with a particularly harmful variety ofbacteriophage, the contents therein could be subjected to sterilizationor disinfection by means of either electrohydraulic shock or exposure toheat. Using electrohydraulic shock, an extremely high voltage, rapidlyoscillating electric current would be sent through the system. By thismeans, the bacteria, which respond to electric charges, would soon betorn apart or otherwise inactivated. Even viruses and bacteriophagewould be destroyed by this means. The advantage of electrohydraulicshock over heat as a means of killing microorganisms, is that lessenergy is needed in order to kill them, hence there is less expense inareas where electricity is competitively priced. In addition, thebacteria, although killed or inactivated, are not utterly destroyed; theenzymes remain active. It should be noted that currents of more thanfive hundred volts and oscillations greater than one hundred per secondcan also be used as an alternative to the autoclaving described above inproducing the final product.

In some cases it may be advisable to dispose of a particularly badprefermentation lot that may happen to develop in the first fermentationtank. A disinfectant could be added in order to destroy any noxiousmicroorganisms. Because the volume of the second tank 14 can beconsiderably greater than the volume of the first tank 12 is is possibleto add a lethal amount of a disinfectant to the first tank, such assodium hypochlorite, then wait until the disinfectant is used up, andfinally to use the resulting sterile mash for fermentation in the secondtank because the disinfectant would be so diluted by that time that itwould not effect the growth of bacteria.

One important alternative system involves the use of a different type ofbacteria and a different type of substrate. In this system sulfurbacteria are used to convert a substrate of sulfur or sulfur compoundsinto sulfuric acid. Oxygen must also be present in order for theoxidation to take place. Although sulfur bacteria are resistant to pHlevels as low as 1.0 it is possible to concentrate the sulfuric acid bymeans of an electrodialysis apparatus or merely by distillation. Theyield of protein and carbon, which is converted from carbon dioxide(which also must necessarily be present) into food would represent anenergy conversion efficiency of up to percent. There would bepractically no danger of contamination with pathogenic bacteria, becauseof the unique medium in which sulfur bacteria grow. Air blasts blowninto the medium are used in order to supply oxygen and the agitationnecessary so that a maximum growth rate occurs. it should be noted thatthis method of protein synthesis is completely independent ofphotosynthesis: the energy of the bacteria is derived from chemicaloxidation of inorganic sulfur compounds or elemental sulfur.

The autotrophic bacteria are also capable of digesting and utilizingother sulfurv compounds, including thiosulfates, sulfites, sulfides, andpyrites. The rate of growth of sulfur bacteria or such substrates iscomparable to the growth rates of cellulolytic bacteria; thus thismethod provides a competitive and unique way by which food and sulfuricacid may be produced.

In the case of sulfide or pyrite ores this process would prove extremelyuseful for the production of metals and purified metallic ores withoutthe usual pollution of sulfurous gases that accompanies smelting. Itwould be necessary to grind the ore to as small a particle size as ispractical. Additional agitation in the fermentation container would benecessary to insure maximum contact with the substrate.

Hydrogen sulfide is also a good source of energy for sulfur bacteria;the gas coming from a volcano would serve as an excellent nutrient forthe bacteria because, in addition to high-energy sulfurous gasescontained therein, ammonia in volcanic gases could supply the nitrogenrequirements of the sulfur bacteria, and other nutrients (e.g.,phosphates, potassium, calcium, and magnesium) are often associated withvolcanos. Thus it would be possible to set up a natural protein-sulfuricacid plant at the mouth of a smoking, dormant volcano, or wherevervolcanic gas is available. Merely by including a suitable water source,which may be sprayed into the volcanic-air atmosphere, it would bepossible to obtain a plant that would require aminimum of labor tooperate. Periodic harvests (perhaps weekly) of the bacterial suspensionand sulfur products would be almost all the necessary maintenance.

Natural gas and coal gas may be bubbled through a system of sulfurbacteria, which would extract only the sulfurous gases, ammonia, carbondioxide and oxygen in the natural gas or coal gas. By this means suchfuel gases could be cleansed of impurities that otherwise would increaseair pollution. Once passed through a battery of sulfur bacteriacontainers, the gas would be substantially free of sulfur, carbondioxide, which reduces the efficiency of fuel gas, ammonia, and oxygen.It might be necessary to add air or oxygen to the gas at the outset inlow percentages. The oxygen would be absorbed and utilized by the sulfurbacteria before the gas reached the end of the battery of biologicalscrubbers, and if air were used the nitrogen content increase would beneglible. Only enough oxygen need be added so that just the sulfur isoxidized.

A similar arrangement is possible for the removal of sulfur from oil. Ata time of growing concern over the sulfur content of fuel and heatingoils, this would provide an economical way by which the sulfur could beremoved. The oil would have to be in small droplets so that its sulfurcontent is available to the bacteria. An inert emulsifying agent couldhelp insure contact of the oil with the aqueous-bacteria phase. Althougha similar arrangement is possible for extracting the sulfur from coal,it would be necessary to grind the coal or otherwise insure that thesulfur could be taken out. One method for removing the sulfur from coalconsists in heating the coal so that the sulfur present is driven off.Whereas the boiling of sulfur is 444.6 Centigrade, many of the sulfurouscomponents of coal would be driven off at moderate temperature; hydrogenpresent in the coal would tend to combine with the sulfur to formhydrogen sulfide. Grinding the coal would tend to be both expensive andless effective as a method of making the sulfur available to bacteria.It should be noted that whereas the energy conversion efficiency ofsulfur bacteria seems to be low, it compares favorably with theefficiency of photosynthesis in green plants.

Another important variation in the process of obtaining food and usefulby-products by means of the microbial decomposition of waste materialsor abundant energy-rich materials consists of using hydrogen andhydrocarbons as substrates for oxidation by bacteria or yeast. Comparedto the sulfur bacteria the autotrophic hydrogen bacteria areapproximately four times as efficient in the use of available energy.Thus the yield is near 30 percent for hydrogen bacteria. Even when inlow, otherwise unusable concentrations, the hydrogen can be utilized ina manner analogous to the scrubbing of sulfurous gases.

Certain bacteria are capable of using hydrocarbons as substrates forenergy. A wide. range of hydrocarbons are suitable as substrate. The twodifficulties involved in utilizing hydrocarbons as a source of energyare first that being nearly insoluble in water, the hydrocarbon isinaccessible to the bacteria that can act upon it and secondly, in thecase of higher hydrocarbons (oils) there is a problem separating thebacteria-containing valuable food from the oily mixture. In accordancewith a feature of the invention, oil shale is used directly as asubstrate for the growth of microorganisms: bacteria are better adaptedfor growth on this type of medium than they are for growing in oil. Oiland water tend to form two distinct layers, and bacteria which need bothcan survive and reproduce only at or near the interface. Violentagitation has been suggested as a means for increasing the surface areaof the oil-water interface. The oil shale is first comminuted so thatthe particles are fine enough to form a suspension in water. Dependingon how fine they are, a more or less violent agitation is applied to thesystem so that the particles do not fall out of suspension. Air issupplied so that the hydrocarbon-utilizing bacteria can grow rapidly.Other conditions including the proper mineral content are assumed. Thismethod of culturing bacteria makes use of an extremely abundant mineralthat otherwise has little economic value. A certain amount of oil canalso be recovered from this process. Carbon dioxide, one of the primarywaste products can be extracted and bottled} if economics warrant. Theuse of an emulsifying agent may be used in order to achieve intimatecontact between the hydrocarbon and bacteria. Some of the hydrocarbonscan be converted into derivitives thereof including higher alcohols andthe carboxylic acids. These too may be utilized by the bacteria andyeast.

One advantage to the system of anaerobic fermentation using cellulolyticmicroorganisms is the possibility it opens for the utilization of algaeincluding both unicellular microscopic algae such as Chlorella and alsothe algae of seaweed. Algae is practically the only variety of greenplant that does not contain lignin in any significant quantity. One ofthe great problems in utilizing algal food is the thick cell wall of thealgae which prevents it from being digested by man to anything near itsnutritional potential and also makes the extraction of proteindifficult. By means of the ability of cellulolytic microorganisms theobstructing matter of the algae will not prevent the full utilization ofits food value once the microorganisms have acted. Although cellulolyticmicroorganisms of the types already mentioned may be capable ofdigesting algae, it is possible to obtain algae-utilizing microorganismfrom a breed of sheep in the Hebrides where they have adapted themselvesto eating a diet consisting solely of sea weed. In addition, the florain the digestive tracts of certain whales, and other aquatic animals maybe used. This possibility opens up prospects for the disposal of sewageseveral hundred miles off a coast. A city with a large sewage disposalproblem that is on or near the coast could tow sewage out to sea whereit would be dropped at an algae farm. The nutrients contained in thesewage would cause a prolific growth of algae as is too well known fromour polluted lakes and rivers. The algae could then be harvested andprocessed right on board ship or it could be taken back to a chemicalfactory for processing. Useful products already obtained from algae maybe extracted. These include agar agar and alginic acid. The residue maythen be subjected to fermentation that will consume the obstructingcellulose and other matter. The final products may then be extracted ashas been described. Wherever there are growths of algae, which areprolific and generally for that reason a nuissance, it becomes possibleto harvest them and use them as a source of food. Because the harvestingof algae will take nutrients out of a polluted system, less will remainfor the putrefaction of that aquatic system.

I claim:

l. A method for the utilization of biodegradable material comprising a.forming an aqueous suspension of comminuted biodegradable wastematerials mixed with a microbiological system of aplurality of severaltypes of microorganisms;

. maintaining said suspension in a fermentation tank under conditionsfor microbial metabolic action to decompose said waste materials insuspension;

. removing from said tank, during and after said metabolic action thegaseous productions of said metabolic action and the portion of saidsuspension resistant to microbial action;

d. separating solid proteineous material in said, suspension after saidmetabolic action from the liquor of the suspensionyand e. extractingliquor components from said liquor by electrodialysis.

2. The method in accordance with claim 1, wherein said biodegradablewaste materials include cellulose and said microbiological systemincludes one or more cellylolytic microorganisms selected from the groupin cluding rumen microorganisms, thermophilic microorganisms, molds andfungi.

3'. The method in accordance with claim 2, wherein said microbiologicalsystem is maintained at a pH 5.0 i 2.0.

4. The method in accordance with claim 1, wherein said solid proteineousmaterial in suspension is separated from the liquor by removing aportion of said suspension from said fermentation tank and treating saidsuspension portion to provide a pH value close to the isoelectric pointof said suspension portion, whereby said solid proteineous material insuspension may coagulate and separate from said suspension liquid.

5. The method in accordance with claim 1, wherein said microbiologicalsystem is maintained in an equilibrium condition by controlling thegrowth of the microorganisms in said system by the ionic concentrationof said suspension determined by the electrodialysis extraction oforganic ions from said liquor of suspension.

6. The method in accordance with claim 5, wherein said equilibriumcondition is also controlled by alkaline neutralizing agents.

7. The method in accordance with claim 5, including the step ofmaintaining the concentration of organic acids in said fermentation tankbetween 0.1 and percent by weight.

8. The method in accordance with claim 1, including the step ofintroducing into said fermentation tank one or more antibiotics andinnocula of bacteria resistant to said antibiotics, wherebynon-resistant bacteria introduced by the addition of new waste materialare eliminated.

9. The method in accordance with claim 1, including the step ofintroducing protozoa into the fermentation tank to'limit the growth ofpathogenic and nonproductive bacteria.

10. The method in accordance with claim 1, wherein the electrodialysisincludes the steps of passing said liquor into an electrodialysis cellseparated by organic ion-selective membranes from an adjacent cell,establishing a dc. potential serially through said cells to concentrateorganic acid and salt ions in said adjacent cell.

11. The method in accordance with claim 10, wherein said organic ionselective membranes are made by forming cellulosic esters of organicacids and fabricating said membranes from cellulose including a selectedone of said cellulosic esters.

12. The method in accordance with claim 10,

wherein said organic selective membranes are formed by heating one ofthe anhydrides of propionic acid, acetic acid or lactic acid withcellulose with or without the presence of sulfuric acid, glacial aceticacid, or pure propionic acid, and fabricating the resulting materialinto thin membranous sheets.

- 13. The method in accordance with claim 10, wherein said organicselective membranes are formed by treating cellophane with glacialacetic acid for about 12 hours at room temperature to become selectiveto acetate ions.

14. The method in accordance with claim 10, including the step ofpassing said liquor continuously into said electrodialysis cell andcontinuously removing concentrated acid and salt ions from said adjacentcell.

15. The method in accordance with claim 14, including the step ofreturning spent liquor from said electrodialysis cell to saidfermentation tank.

16. The method in accordance with claim 1, including the step of passingsaid liquor into a plurality of electrodialysis cells each separatedfrom a different adjacent cell by a membrane selective to a differentorganic ion, whereby said different organic ions are removed from saidliquor and concentrated in different adjacent cells.

17. The method in accordance with claim 5, wherein the equilibrium ofthe microbiological system is maintained by controlling the rate ofliquor flowing through said electrodialysis apparatus and returned tosaid fermentation tank.

18. The method in accordance with claim 1, including the step of addingone or more steering agents to said suspension to control the type andyield of said products of fermentation.

19. The method in accordance with claim 1, including the step of addinga derivative of acetic acid as a steering agent to said suspension toinhibit acetic acid production as a product of fermentation.

20. The method in accordance with claim 1, including the step of addingsmall quantities of carbon tetrachloride to said suspension to inhibitmethane production as a product of fermentation.

21. The method in accordance with claim 1, wherein said microbiologicalsystem is retained in an equilibrium condition by controlling thefollowing factors, (a) the nature and concentration of the substrate,(b) the type of bacteria used in said system, (c) the amount and kind orsteering agents used, (d) the rate of withdrawal of organic acids fromsaid system by electrodialysis, and the concentration of alkali metalions to control the pH of said system.

22. The method in accordance with claim 21, wherein said equilibriumcondition is maintained by holding the concentration of organic acids inthe system between 0.1 and 10 percent..

23. The method in accordance with claim 1, wherein said liquor includesalcohols and acetone, including the steps of removing said alcohols andacetone from said liquor by mixing said liquor with gasoline to dissolvethe alcohols and acetone in the gasoline, and separating said alcohol,acetone and gasoline mixture from said liquor.

24. The method in accordance with claim 1, wherein said solidproteineous material separated from said suspension is processed intofood by autolyzing by the step of electrohydraulic shock to releaseenzymes from the bacteria in said proteineous material.

25. The method in accordance with claim 24, wherein said solidproteineous material is processed into food by autolyzing said materialby the step of exposing said material to a high voltage alternatingpotential to disrupt the lysosomes of said bacteria in said proteineousmaterial. 1

26. The method in accordance with claim 1, wherein said porteineousmaterial is processed into food by forming said proteineous materialinto fibers.

27. The method in accordance with claim 1, wherein said proteineousmaterial is processed into food by the steps of forming a concentratedsolution of said proteineous material, forcing said concentratedsolution through spinnerets into pure cold water to coagulate saidproteineous material into fibers, and binding the fibers together withgelatin.

28. The method in accordance with claim 1, wherein said proteineousmaterial is processed by the steps of adding to said proteineousmaterial cheese curing bacteria and molds, adding to the proteineousmaterial one or more of a curdled proteineous material, a polysaccharideor derivative thereof, starch, or a cellulose derivative.

29. The method in accordance with claim I, wherein said proteineousmaterial is processed by the step of composting said material to breakdown portions of said proteineous material resistant to bacterialaction, and processing the composted proteineous material by repeatingthe method steps (a) through (e).

30. A method in accordance with claim 1, wherein said aqueous suspensionincludes sulfur or sulfur compounds and sulfur bacteria are included insaid aqueous suspension to convert the sulfur and sulfur compounds tosulfuric acid as a product of said fermentation.

31. The method in accordance with claim 30, wherein said sulfurcompounds include finely ground sulfide ores, and said suspension isagitated by bubbling through said suspension one or more of hydrogensulfide gas, the gases obtained from volcanic action, natural gas, andcoal gas.

32. The method in accordance with claim 30, wherein said sulfurcompounds are contained in oil and said suspension includes an emulsionof said oil.

33. The method in accordance with claim 30, wherein said sulfurcompounds are contained in coal and said suspension includes said coalin a finely div material vided state.

34. The method in accordance with claim 1, wherein said aqueoussuspension includes a hydrocarbon oil and hydrogen bacteria or yeast,and the method includes the step of agitating the suspension to increasethe oil-water interface.

35. The method in accordance with claim 34, wherein the hydrocarbon oilis contained in oil shale, and the method includes the step ofcomminuting the oil shale to a fineness providing a suspension of saidshale in water.

36. The method in accordance with claim 35, wherein an emulsifying agentis added to the suspension of fine shale particles to increase theoil-water interface.

37. The method in accordance with claim 1, wherein said aqueoussuspension includes resistant organic material, said method includingthe steps of separating said resistant organic material from saidsuspension, processing said resistant organic material by forming acompost of said organic material, adding nutrients to said compost tobreak down portions of said organic resistant to bacterial action toform a proteinaceous product, hydrolyzing the proteinaceous product withhot acid or alkali, or by means of enzymes.

2. The method in accordance with claim 1, wherein said biodegradablewaste materials include cellulose and said microbiological systemincludes one or more cellylolytic microorganisms selected from the groupincluding rumen microorganisms, thermophilic microorganisms, molds andfungi.
 3. The method in accordance with claim 2, wherein saidmicrobiological system is maintained at a pH 5.0 + or - 2.0.
 4. Themethod in accordance with claim 1, wherein said solid proteineousmaterial in suspension is separated from the liquor by removing aportion of said suspension from said fermentation tank and treating saidsuspension portion to provide a pH value close to the isoelectric pointof said suspension portion, whereby said solid proteineous material insuspension may coAgulate and separate from said suspension liquid. 5.The method in accordance with claim 1, wherein said microbiologicalsystem is maintained in an equilibrium condition by controlling thegrowth of the microorganisms in said system by the ionic concentrationof said suspension determined by the electrodialysis extraction oforganic ions from said liquor of suspension.
 6. The method in accordancewith claim 5, wherein said equilibrium condition is also controlled byalkaline neutralizing agents.
 7. The method in accordance with claim 5,including the step of maintaining the concentration of organic acids insaid fermentation tank between 0.1 and 10 percent by weight.
 8. Themethod in accordance with claim 1, including the step of introducinginto said fermentation tank one or more antibiotics and innocula ofbacteria resistant to said antibiotics, whereby non-resistant bacteriaintroduced by the addition of new waste material are eliminated.
 9. Themethod in accordance with claim 1, including the step of introducingprotozoa into the fermentation tank to limit the growth of pathogenicand nonproductive bacteria.
 10. The method in accordance with claim 1,wherein the electrodialysis includes the steps of passing said liquorinto an electrodialysis cell separated by organic ion-selectivemembranes from an adjacent cell, establishing a d.c. potential seriallythrough said cells to concentrate organic acid and salt ions in saidadjacent cell.
 11. The method in accordance with claim 10, wherein saidorganic ion selective membranes are made by forming cellulosic esters oforganic acids and fabricating said membranes from cellulose including aselected one of said cellulosic esters.
 12. The method in accordancewith claim 10, wherein said organic selective membranes are formed byheating one of the anhydrides of propionic acid, acetic acid or lacticacid with cellulose with or without the presence of sulfuric acid,glacial acetic acid, or pure propionic acid, and fabricating theresulting material into thin membranous sheets.
 13. The method inaccordance with claim 10, wherein said organic selective membranes areformed by treating cellophane with glacial acetic acid for about 12hours at room temperature to become selective to acetate ions.
 14. Themethod in accordance with claim 10, including the step of passing saidliquor continuously into said electrodialysis cell and continuouslyremoving concentrated acid and salt ions from said adjacent cell. 15.The method in accordance with claim 14, including the step of returningspent liquor from said electrodialysis cell to said fermentation tank.16. The method in accordance with claim 1, including the step of passingsaid liquor into a plurality of electrodialysis cells each separatedfrom a different adjacent cell by a membrane selective to a differentorganic ion, whereby said different organic ions are removed from saidliquor and concentrated in different adjacent cells.
 17. The method inaccordance with claim 5, wherein the equilibrium of the microbiologicalsystem is maintained by controlling the rate of liquor flowing throughsaid electrodialysis apparatus and returned to said fermentation tank.18. The method in accordance with claim 1, including the step of addingone or more steering agents to said suspension to control the type andyield of said products of fermentation.
 19. The method in accordancewith claim 1, including the step of adding a derivative of acetic acidas a steering agent to said suspension to inhibit acetic acid productionas a product of fermentation.
 20. The method in accordance with claim 1,including the step of adding small quantities of carbon tetrachloride tosaid suspension to inhibit methane production as a product offermentation.
 21. The method in accordance with claim 1, wherein saidmicrobiological system is retained in an equilibrium condition bycontrolling the following factors, (a) the nature and concentration ofthe suBstrate, (b) the type of bacteria used in said system, (c) theamount and kind or steering agents used, (d) the rate of withdrawal oforganic acids from said system by electrodialysis, and the concentrationof alkali metal ions to control the pH of said system.
 22. The method inaccordance with claim 21, wherein said equilibrium condition ismaintained by holding the concentration of organic acids in the systembetween 0.1 and 10 percent.
 23. The method in accordance with claim 1,wherein said liquor includes alcohols and acetone, including the stepsof removing said alcohols and acetone from said liquor by mixing saidliquor with gasoline to dissolve the alcohols and acetone in thegasoline, and separating said alcohol, acetone and gasoline mixture fromsaid liquor.
 24. The method in accordance with claim 1, wherein saidsolid proteineous material separated from said suspension is processedinto food by autolyzing by the step of electrohydraulic shock to releaseenzymes from the bacteria in said proteineous material.
 25. The methodin accordance with claim 24, wherein said solid proteineous material isprocessed into food by autolyzing said material by the step of exposingsaid material to a high voltage alternating potential to disrupt thelysosomes of said bacteria in said proteineous material.
 26. The methodin accordance with claim 1, wherein said porteineous material isprocessed into food by forming said proteineous material into fibers.27. The method in accordance with claim 1, wherein said proteineousmaterial is processed into food by the steps of forming a concentratedsolution of said proteineous material, forcing said concentratedsolution through spinnerets into pure cold water to coagulate saidproteineous material into fibers, and binding the fibers together withgelatin.
 28. The method in accordance with claim 1, wherein saidproteineous material is processed by the steps of adding to saidproteineous material cheese curing bacteria and molds, adding to theproteineous material one or more of a curdled proteineous material, apolysaccharide or derivative thereof, starch, or a cellulose derivative.29. The method in accordance with claim 1, wherein said proteineousmaterial is processed by the step of composting said material to breakdown portions of said proteineous material resistant to bacterialaction, and processing the composted proteineous material by repeatingthe method steps (a) through (e).
 30. A method in accordance with claim1, wherein said aqueous suspension includes sulfur or sulfur compoundsand sulfur bacteria are included in said aqueous suspension to convertthe sulfur and sulfur compounds to sulfuric acid as a product of saidfermentation.
 31. The method in accordance with claim 30, wherein saidsulfur compounds include finely ground sulfide ores, and said suspensionis agitated by bubbling through said suspension one or more of hydrogensulfide gas, the gases obtained from volcanic action, natural gas, andcoal gas.
 32. The method in accordance with claim 30, wherein saidsulfur compounds are contained in oil and said suspension includes anemulsion of said oil.
 33. The method in accordance with claim 30,wherein said sulfur compounds are contained in coal and said suspensionincludes said coal in a finely divided state.
 34. The method inaccordance with claim 1, wherein said aqueous suspension includes ahydrocarbon oil and hydrogen bacteria or yeast, and the method includesthe step of agitating the suspension to increase the oil-waterinterface.
 35. The method in accordance with claim 34, wherein thehydrocarbon oil is contained in oil shale, and the method includes thestep of comminuting the oil shale to a fineness providing a suspensionof said shale in water.
 36. The method in accordance with claim 35,wherein an emulsifying agent is added to the suspension of fine shaleparticles to increase the oil-water interface.
 37. The method inaccordance with claim 1, wherein Said aqueous suspension includesresistant organic material, said method including the steps ofseparating said resistant organic material from said suspension,processing said resistant organic material by forming a compost of saidorganic material, adding nutrients to said compost to break downportions of said organic material resistant to bacterial action to forma proteinaceous product, hydrolyzing the proteinaceous product with hotacid or alkali, or by means of enzymes.